Effect of Storage Conditions on Pollen Grains Viability and Pollen Tubes Elongation of Four Cola Species (Malvaceae)Author(s): Emmanuel Youmbi, Libert Brice Tonfack, Jean Bernard Donfack Mbogning and Bernard-Alays Nkongmeneck
Self incompatibility and variability in the flowering time of different species of kola trees are the major factors that deeply affect the productivity of these plants. It seems absolutely important to conserve the pollen viability in order to create gene banks for Cola spp. breeding programmes. In this study, 3 cultivated Cola species (C. ballayi, C. acuminata and C. anomala) and one wild species (C. lepidota) were used to estimate, using in vitro germination tests, the pollen viability of fresh pollen and dehydrated pollen grains stored during 8 weeks at ïÂ20°C and 10°C. The tube length growth of fresh and stored pollen was also evaluated. Results showed that fresh pollen grains better conserved their germination potential than dehydrated pollen grains for all the four species. Germination capacities were better preserved at ïÂ20°C for non dehydrated pollen of C. ballayi (8 weeks), C. acuminata (7 weeks) and C. lepidota (5 weeks), and at 10°C for C. anomala (7 weeks). The pollen tube lengths decrease as the period of conservation lasts, for all species. These results are basically very important and applicable in breeding programmes to create new hybrids and improve Cola plant species.